Pipe joining structure

ABSTRACT

A pipe joining structure adapted to join a pipe to a fluid passage of an equipment housing. An end portion of a pipe is bent by about 90 degrees to form a bend portion and a tip of the bend portion is fitted into an opening of the fluid passage. The pipe joining structure includes a stay fitted over the bend portion of the pipe, a tip of the pipe is formed with a flange, and an O-ring fitted between the stay and the flange of the pipe. The tip of the pipe is joined to the equipment housing by fixing the stay to the equipment housing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser. No. 13/508,760 filed May 9, 2012 which is a U.S. national stage application of PCT/JP2010/070641 filed on Nov. 12, 2010, and claims priority to, and incorporates by reference, Japanese Patent Application No. 2009-263688 filed on Nov. 19, 2009.

TECHNICAL FIELD

The present invention relates to a pipe joining structure. More specifically, the present invention relates to a pipe joining structure for coupling a pipe disposed to extend along a surface of an equipment housing which houses therein a transmission, an engine or the like, to an opening portion of a fluid passage of an equipment case.

BACKGROUND ART

In a transmission, for example, an oil pipe disposed to extend along a surface of a housing has an oil pipe end which is coupled to an opening portion of a fluid passage of the housing by means of a joint, as described in Japanese Patent Application Laid-open No. 2003-106493.

More specifically, the technique disclosed in this patent document is such that the pipe is joined to the fluid passage of the housing by attaching an eyejoint to an end portion of the pipe and then coupling the eyejoint to the opening portion of the fluid passage of the housing by means of an eyebolt.

The pipe joining structure disclosed in the patent document noted above, however, requires two washers in addition to the eye joint and eyebolt and hence requires an increased parts count, which results in an increased parts cost as well as an increased number of management items due to an increased number of seal portions.

DISCLOSURE OF THE INVENTION

The present invention has been made with the above-described actual condition of the background art in view. An object of the present invention is to provide a pipe joining structure which allows the parts cost to be reduced while requiring a reduced number of seal portions.

In order to accomplish the above-described object, the present invention provides a first pipe joining structure for joining a pipe disposed to extend along an equipment housing to a fluid passage of the equipment housing by bending an end portion of the pipe about 90 degrees to form a bend portion and fitting a tip of the bend portion into an opening of the fluid passage, characterized in that: a stay is fitted over the bend portion of the pipe; a tip of the pipe is formed with a flange; an O-ring is fitted between the stay and the flange of the pipe; and the stay is fixed to the equipment housing, to thereby join the tip of the pipe to the equipment housing.

The first pipe joining structure according to the present invention may have an arrangement wherein the bend portion of the pipe is formed with two spools, while the stay is held between the spools.

In order to accomplish the above-described object, the present invention provides a second pipe joining structure for joining a pipe disposed to extend along an equipment housing to a fluid passage of the equipment housing by bending an end portion of the pipe about 90 degrees to form a bend portion and fitting a tip of the bend portion into an opening of the fluid passage, characterized in that: a stay is provided which has a central portion formed with a tubular projecting portion having a tip formed with a flange and an intermediate portion formed with a spool; a tip of the pipe is fitted into and fixed to a pipe insert hole of the tubular projecting portion of the stay; an O-ring is fitted between the flange and the spool of the stay; the tubular projecting portion of the stay is fitted into the fluid passage of the equipment housing; and the stay is fixed to the equipment housing, to thereby join the tip of the pipe to the equipment housing.

In order to accomplish the above-described object, the present invention provides a third pipe joining structure for joining a pipe disposed to extend along an equipment housing to a fluid passage of the equipment housing by bending an end portion of the pipe about 90 degrees to form a bend portion and fitting a tip of the bend portion into an opening of the fluid passage, characterized in that: a stay is provided which has a central portion formed with a tubular projecting portion having an intermediate portion formed with a spool; a tip of the pipe is fitted into and fixed to a pipe insert hole of the tubular projecting portion of the stay; an O-ring is fitted between the spool formed on the tubular projecting portion of the stay and a base portion of the tubular projecting portion; the tubular projecting portion of the stay is fitted into the fluid passage of the equipment housing; and the stay is fixed to the equipment housing, to thereby join the tip of the pipe to the equipment housing.

In order to accomplish the above-described object, the present invention provides a fourth pipe joining structure for joining a pipe disposed to extend along an equipment housing to a fluid passage of the equipment housing by bending an end portion of the pipe about 90 degrees to form a bend portion and fitting a tip of the bend portion into an opening of the fluid passage, characterized in that: a joint is fixed to the tip of the bend portion while being locked by a stay; an O-ring is fitted over a peripheral surface of the joint; and the stay is fixed to the equipment housing, to thereby join a tip of the pipe to the equipment housing.

In order to accomplish the above-described object, the present invention provides a fifth pipe joining structure for joining a pipe disposed to extend along an equipment housing to a fluid passage of the equipment housing by bending an end portion of the pipe about 90 degrees to form a bend portion and fitting a tip of the bend portion into an opening of the fluid passage, characterized in that: a joint is fixed to the tip of the bend portion; an O-ring is fitted over a peripheral surface of the joint; and the joint is locked onto the equipment housing by means of a one-touch type retainer, to thereby join a tip of the pipe to the equipment housing.

With the first to fifth pipe joining structures according to the present invention, each having an arrangement wherein the end portion of the pipe is bent to form the bend portion having a tip fitted into the opening of the fluid passage of the equipment housing, while the O-ring provides a seal between the outer periphery of the pipe fitted into the fluid passage and the inner periphery of the fluid passage, it is possible to realize compact pipe joining with a lower parts count by minimum right angle bending of the pipe and reduce the number of seal portions, thereby to make management easy. Further, easy pipe joining becomes possible because the O-ring for sealing is positioned in place with less possibility of its falloff by being fitted between the flange formed at the tip of the pipe and the stay or between the flange formed at the tip of the pipe and the spool or by being fitted over the peripheral surface of the joint fixed to the tip of the pipe or otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view illustrating one embodiment of a pipe joining structure according to the present invention;

FIG. 2 is a sectional view illustrating a variation of the pipe joining structure shown in FIG. 1;

FIG. 3 is a sectional view illustrating another embodiment of a pipe joining structure according to the present invention;

FIG. 4 is a sectional view illustrating a variation of the pipe joining structure shown in FIG. 3;

FIG. 5 is a sectional view illustrating yet another embodiment of a pipe joining structure according to the present invention; and

FIG. 6 is a sectional view illustrating a variation of the pipe joining structure shown in FIG. 5.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of pipe joining structures according to the present invention will be described in detail with reference to the drawings.

In a pipe joining structure 10 illustrated in FIG. 1, a fluid passage 11 a formed in an equipment housing 11 which houses therein a clutch, an engine or the like has an opening portion formed with a spot-faced hole 11 b. An opening peripheral edge around the spot-faced hole 11 b is formed with a female thread hole 11 c.

A pipe 12 disposed to extend along a surface of the equipment housing 11 has an end portion which is bent about 90 degrees by minimum right angle bending to form a bend portion 12 a. The tip of the bend portion 12 a is formed with a flange 12 b by curling or the like.

The pipe joining structure 10 has a stay 13. The stay 13 comprises a sheet member 13 a having a central portion which is formed with a pipe insert hole 13 c having a tubular projecting portion 13 b formed by burring or the like. A screw insert hole 13 d is formed between the pipe insert hole 13 c and a peripheral edge. The sheet member 13 a is partially formed with a tongue-like piece 13 e which is bent like a crank to extend in the opposite direction away from the tubular projecting portion 13 b. With the pipe insert hole 13 c of the stay 13 being fitted over the bend portion 12 a of the pipe 12, the tubular projecting portion 13 b and the tongue-like piece 13 e are fixed to the bend portion 12 a and a straight pipe portion 12 c, respectively, of the pipe 12 by brazing or the like.

The fixing between the tubular projecting portion 13 b and the bend portion 12 a of the pipe 12 and the fixing between the tongue-like piece 13 e and the straight pipe portion 12 c of the pipe 12 are not necessarily required. However, such fixing therebetween allows the stay 13 to be easily positioned relative to the pipe 12 while facilitating the fitting operation on the equipment housing 11.

In the pipe joining structure 10, the bend portion 12 a of the pipe 12 is fitted into the spot-faced hole 11 b of the equipment housing 11 with an O-ring 14 fitted between the flange 12 b of the bend portion 12 a of the pipe 12 and the tip of the tubular projecting portion 13 b of the stay 13. Thereafter, a screw 15 is inserted into the screw insert hole 13 d of the stay 13 and then the tip of the screw 15 is threadingly engaged with the female thread hole 11 c of the equipment housing 11 to fasten the pipe 12 to the equipment housing 11.

The pipe joining structure 10 thus assembled restrains the O-ring 14 between the flange 12 b of the pipe 12 and the tubular projecting portion 13 b of the stay 13 to provide a seal between the peripheral surface of the pipe 12 and the spot-faced hole 11 b of the equipment housing 11. Further, the pipe 12 is joined to the equipment housing 11 by means of the stay 13.

In a pipe joining structure 20 illustrated in FIG. 2, a fluid passage 21 a formed in an equipment housing 21 has an opening portion formed with a spot-faced hole 21 b. An opening peripheral edge around the spot-faced hole 21 b is formed with a female thread hole 21 c.

A pipe 22 disposed to extend along a surface of the equipment housing 21 has an end portion which is bent about 90 degrees by minimum right angle bending to form a bend portion 22 a. The tip of the bend portion 22 a is formed with a flange 22 b by curling or the like. The pipe 22 is further formed with spools 22 c and 22 d at an intermediate portion of the bend portion 22 a. These spools 22 c and 22 d are provided for holding therebetween a stay 23 to be described later and are formed by end forming after the stay 23 has been fitted over the bend portion 22 a of the pipe 22.

The stay 23 comprises a substantially circular sheet member 23 a having a central portion which is formed with a pipe insert hole 23 b. A screw insert hole 23 c is formed between the pipe insert hole 23 b and a peripheral edge. A tongue-like piece 23 d extends from a part of the sheet member 23 a and is bent upwardly like a crank.

With the pipe insert hole 23 b of the stay 23 being fitted over the bend portion 22 a of the pipe 22, the spools 22 c and 22 d are formed by end forming to sandwich the sheet member 23 a of the stay 23 therebetween. The peripheral edge portion of the pipe insert hole 23 b and the tongue-like piece 23 d are fixed to between the spools 22 c and 22 d of the pipe 22 and to a straight pipe portion 22 e of the pipe 22, respectively, by brazing or the like.

The fixing between the peripheral edge portion of the pipe insert hole 23 b and the spools 22 c and 22 d of the pipe 22 and the fixing between the tongue-like piece 23 d and the straight pipe portion 22 e of the pipe 22 are not necessarily required. However, such fixing therebetween allows the stay 23 to be easily positioned relative to the pipe 22 while facilitating the fitting operation on the equipment housing 21.

Subsequently, an O-ring 24 is fitted between the flange 22 b and the spool 22 c and then the tip of the bend portion 22 a of the pipe 22 is fitted into the spot-faced hole 21 b of the equipment housing 21. Thereafter, a screw 25 is inserted into the screw insert hole 23 c of the stay 23 and then the tip of the screw 15 is threadingly engaged with the female thread hole 21 c of the equipment housing 21 to fasten the pipe 22 to the equipment housing 21.

The pipe joining structure 20 thus assembled restrains the O-ring 24 between the flange 22 b and the spool 22 c of the pipe 22 to provide a seal between the peripheral surface of the pipe 22 and the spot-faced hole 21 b of the equipment housing 21. Since the spools 22 c and 22 d of the pipe 22 are engaged by the stay 23, the pipe 22 is joined to the equipment housing 21 by means of the stay 23.

In a pipe joining structure 30 illustrated in FIG. 3, a fluid passage 31 a formed in an equipment housing 31 has an opening portion formed with a spot-faced hole 31 b. An opening peripheral edge around the spot-faced hole 31 b is formed with a female thread hole 31 c.

A pipe 32 disposed to extend along a surface of the equipment housing 31 has an end portion which is bent about 90 degrees by minimum right angle bending.

The pipe joining structure 30 has a stay 33. The stay 33 comprises a sheet member 33 a having a central portion which is formed with a tubular projecting portion 33 b by burring or the like. The tubular projecting portion 33 b has a tip formed with a flange 33 c and an intermediate portion formed with a spool 33 d. A screw insert hole 33 f is formed between a pipe insert hole 33 e defined by the tubular projecting portion 33 b and a peripheral edge. The tubular projecting portion 33 b of the stay 33 is fixed to a bend portion 32 a of the pipe 32 by brazing or the like.

In the pipe joining structure 30, the tubular projecting portion 33 b of the stay 33 is fitted into the spot-faced hole 31 b of the equipment housing 31 with an O-ring 34 fitted between the flange 33 c and the spool 33 d of the tubular projecting portion 33 b of the stay 33. Thereafter, a screw 35 is inserted into the screw insert hole 33 f of the stay 33 and then the tip of the screw 35 is threadingly engaged with the female thread hole 31 c of the equipment housing 31 to fasten the pipe 32 to the equipment housing 31.

The pipe joining structure 30 thus assembled restrains the O-ring 34 between the flange 33 c and the spool 33 d of the stay 33 to provide a seal between the tubular projecting portion 33 b of the stay 33 and the spot-faced hole 31 b of the equipment housing 31. Then, the pipe 32 is joined to the equipment housing 31 by means of the stay 33.

In a pipe joining structure 40 illustrated in FIG. 4, a fluid passage 41 a formed in an equipment housing 41 has an opening portion formed with a spot-faced hole 41 b. An opening peripheral edge around the spot-faced hole 41 b is formed with a female thread hole 41 c.

A pipe 42 disposed to extend along a surface of the equipment housing 41 has an end portion which is bent about 90 degrees by minimum right angle bending.

The pipe joining structure 40 has a stay 43. The stay 43 comprises a sheet member 43 a having a central portion which is formed with a tubular projecting portion 43 c by burring or the like. The tubular projecting portion 43 c has a tip portion formed with a spool 43 b. A screw insert hole 43 e is formed between a pipe insert hole 43 d defined by the tubular projecting portion 43 c and a peripheral edge. The tubular projecting portion 43 c of the stay 43 is fixed to a bend portion 42 a of the pipe 42 by brazing or the like.

In the pipe joining structure 40, the tubular projecting portion 43 c of the stay 43 is fitted into the spot-faced hole 41 b of the equipment housing 41 with an O-ring 44 fitted between the spool 43 b of the tubular projecting portion 43 c of the stay 43 and a base portion 43 f of the tubular projecting portion 43 c . A screw 45 is inserted into the screw insert hole 43 e of the stay 43 and then the tip of the screw 45 is threadingly engaged with the female thread hole 41 c of the equipment housing 41 to fasten the pipe 42 to the equipment housing 41.

The pipe joining structure 40 thus assembled restrains the O-ring 44 between the spool 43 b and the base portion 43 f of the stay 43 to provide a seal between the tubular projecting portion 43 c of the stay 43 and the spot-faced hole 41 b of the equipment housing 41. Then, the pipe 42 is joined to the equipment housing 41 by means of the stay 43.

In a pipe joining structure 50 illustrated in FIG. 5, a fluid passage 51 a formed in an equipment housing 51 has an opening portion formed with a spot-faced hole 5 b. An opening peripheral edge around the spot-faced hole 51 b is formed with a female thread hole 51 c.

A pipe 52 disposed to extend along a surface of the equipment housing 51 has an end portion which is bent about 90 degrees by minimum right angle bending to form a bend portion 52 a. The tip of the bend portion 52 a is fitted with a joint 53. The joint 53 has an intermediate portion provided with a flange-shaped portion 53 a, a base end peripheral edge formed with an annular notch 53 b, and a tip peripheral surface formed with an annular recess 53 c.

The pipe joining structure 50 has a stay 54. The stay 54 comprises a sheet member 54 a having a central portion which is formed with a joint insert hole 54 b. A screw insert hole 54 c is formed between the joint insert hole 54 b and a peripheral edge. A tongue-like piece 54 d extends from a part of the sheet member 54 a and is bent upwardly like a crank.

In the pipe joining structure 50, with the joint insert hole 54 b of the stay 54 being fitted over the annular notch 53 b of the joint 53, an opening portion of the joint 53 is fitted over and brazed to the tip of the bend portion 52 a of the pipe 52, while a peripheral edge portion of the joint insert hole 54 b and the tongue-like piece 54 d are fixed to the annular notch 53 b of the joint 53 and a straight pipe portion 52 b of the pipe 52, respectively, by brazing or the like.

The fixing between the peripheral edge portion of the joint insert hole 54 b of the stay 54 and the annular notch 53 b of the joint 53 and the fixing between the tongue-like piece 54 d and the straight pipe portion 52 b of the pipe 52 are not necessarily required. However, such fixing therebetween allows the stay 54 to be easily positioned relative to the pipe 52 while facilitating the fitting operation on the equipment housing 51.

Subsequently, an O-ring 55 is fitted over the annular recess 53 c of the joint 53 and then the tip of the joint 53 is fitted into the spot-faced hole 51 b of the equipment housing 51. Thereafter, a screw 56 is inserted into the screw insert hole 54 c of the stay 54 and then the tip of the screw 56 is threadingly engaged with the female thread hole 51 c of the equipment housing 51 to fasten the pipe 52 to the equipment housing 51.

The pipe joining structure 50 thus assembled restrains the O-ring 55 in the annular recess 53 c of the joint 53 to make the O-ring 55 abut against the internal surface of the spot-faced hole 51 b of the equipment housing 51, thereby providing a seal between the joint 53 and the equipment housing 51. Further, the pipe 52 is joined to the equipment housing 51 via the joint 53 by means of the stay 54.

In a pipe joining structure 60 illustrated in FIG. 6, a fluid passage 61 a formed in an equipment housing 61 has an opening portion formed with a spot-faced hole 61 b. The opening of the spot-faced hole 61 b is formed with a larger-diameter recess 61 c. The recess 61 c has an opening peripheral edge formed with a flange 61 d.

A pipe 62 disposed to extend along a surface of the equipment housing 61 has an end portion which is bent about 90 degrees by minimum right angle bending to form a bend portion 62 a. The tip of the bend portion 62 a is fitted with a joint 63.

The joint 63 has an intermediate portion provided with a flange-shaped portion 63 a, a base end peripheral edge formed with an annular notch 63 b, and a tip peripheral surface formed with an annular recess 63 c.

The pipe joining structure 60 has a one-touch type retainer 64. The retainer 64 is in the form of a truncated cone and is provided with elastic pieces 64 a at suitable places on the peripheral surface of the retainer 64, for example, at two opposite places. Each of the elastic pieces 64 a has an outer peripheral surface formed with a recess 64 b.

In the pipe joining structure 60, an opening portion of the joint 63 is fitted over and brazed to the tip of the bend portion 62 a of the pipe 62. Subsequently, an O-ring 65 is fitted over the annular recess 63 c of the joint 63 and then the tip of the joint 63 is fitted into the spot-faced hole 61 b of the equipment housing 61. Thereafter, the one-touch type retainer 64 is forced into the recess 61 c of the equipment housing 61 against the biasing force of the elastic pieces 64 a and then the annular recess 64 b is brought into engagement with the flange 61 d of the equipment housing 61 with the tip of the joint 63 abutted against the flange-shaped portion 63 a.

The pipe joining structure 60 thus assembled restrains the O-ring 65 in the annular recess 63 c of the joint 63 to make the O-ring 55 abut against the internal surface of the spot-faced hole 61 b of the equipment housing 61, thereby providing a seal between the joint 63 and the equipment housing 61. Further, the pipe 62 is joined to the equipment housing 61 very easily by means of the one-touch type retainer 64.

While the embodiments of the pipe joining structures according to the present invention have been described above, the present invention is in no way limited to the embodiments described above. It is obvious that various variations and modifications are possible within the scope of the technical concept of the present invention defined by the claims.

INDUSTRIAL APPLICABILITY

With the pipe joining structures according to the present invention each having an arrangement wherein the end portion of the pipe is bent to form the bend portion having a tip fitted into the opening of the fluid passage of the equipment housing, while the O-ring provides a seal between the outer periphery of the pipe fitted into the fluid passage and the inner periphery of the fluid passage of the equipment housing, it is possible to realize compact pipe joining with a lower parts count by minimum right angle bending of the pipe and reduce the number of seal portions, thereby to make management easy. Further, easy pipe joining becomes possible because the O-ring for sealing is positioned in place with less possibility of its falloff by being fitted between the flange formed at the tip of the pipe and the stay or between the flange formed at the tip of the pipe and the spool or by being fitted over the peripheral surface of the joint fixed to the tip of the pipe or otherwise. Therefore, the pipe joining structure can be advantageously utilized to couple a pipe disposed to extend along a surface of an equipment housing which houses therein a transmission, an engine or the like, to an opening portion of a fluid passage of an equipment case. 

The invention claimed is:
 1. A pipe joining structure for joining a pipe disposed to extend along an equipment housing to a fluid passage of the equipment housing by bending an end portion of the pipe about 90 degrees to form a bend portion having a tip and a straight portion, the pipe joining structure comprising: a stay including a sheet member having a thin and flat shape with a central portion, the sheet member including a pipe insertion hole provided in the central portion and a peripheral portion extending in a radial direction from a boundary of the pipe insertion hole, the peripheral portion including a screw insert hole for fixing the stay to the equipment housing, and a tubular member integrally formed with the sheet member, the tubular member including a tubular projecting portion extending axially from the boundary of the pipe insert hole of the central portion of the sheet member for insertion into the fluid passage of the equipment housing; the tubular projecting portion having an upper end joined to the boundary of the pipe insertion hole, a bottom end, a middle portion provided axially between the upper and bottom ends of the tubular projecting portion, an intermediate projecting portion extending outwardly in a radial direction from the middle portion of the tubular projecting portion member, and a spool including the intermediate projecting portion; and an O-ring is fitted within the spool of the tubular projecting portion, wherein: the tip of the pipe is fitted within the pipe insert hole of the central portion of the stay and into the tubular projecting portion of the tubular member, the bottom end of the tubular projecting portion of the tubular member is inserted into a spot-faced hole of the opening of the fluid passage of the equipment housing, and the sheet member of the stay is fixed to the equipment housing using the screw insert hole in the sheet member, thereby connecting the tip of the pipe to the equipment housing, and the O-ring provides a seal between the tubular projecting portion of the tubular member and the spot-faced hole.
 2. The pipe joining structure according to claim 1, wherein the spot-faced hole is coaxially arranged with the fluid passage, the spot-faced hole and the intermediate projecting portion of the tubular member both have a diameter greater than inner portions of the fluid passage, the bottom end of the tubular member comprises a flange projecting outwardly in the radial direction of the tubular member, the spool is formed between the intermediate projecting portion and the flange of the tubular member, and the end portion of the pipe is fixed to the tubular member of the stay by brazing.
 3. The pipe joining structure according to claim 1, wherein the spot-faced hole is coaxially arranged with the fluid passage, the spot-faced hole and the intermediate projecting portion of the tubular member both have a diameter greater than inner portions of the fluid passage, the bottom end of the tubular member has a diameter less than the inner portions of the fluid passage, the bottom end of the tubular member is received in the fluid passage, the spool is provided above and adjacent the intermediate projecting portion of the tubular member, the tip of the bend portion of the pipe abuts a peripheral edge contained within the spot-faced hole, and the end portion of the pipe is fixed to the tubular member of the stay by brazing.
 4. A pipe joining structure for joining a pipe extending along an equipment housing to a fluid passage of the equipment housing, the pipe joining structure comprising: a pipe having a bent portion between straight portions of the pipe, the bent portion including a pipe portion bent of about 90 degrees, one straight portion of the pipe having an end portion with a tip configured to be inserted into the fluid passage of the equipment housing, and another straight portion of the pipe configured to extend along the equipment housing; a stay including a tubular member and a sheet member having a thin and flat shape being integrally formed with the tubular member, one side of the sheet member of the stay being an equipment-housing side and an another side of the sheet member opposite the one side being an external-facing side, the equipment-housing side of the sheet member of the stay abutting a surface of the equipment housing when the stay is fitted to the equipment housing, a pipe insertion hole being provided in a central portion of the sheet member, the tubular member extending from a periphery of the pipe insertion hole in the sheet member and into the fluid passage of the equipment when the stay is fitted to the equipment housing, the tubular member including a projecting portion extending outwardly in a radial direction of the tubular member, a spool provided adjacent the projecting portion, and an O-ring is fitted within the spool of the tubular member, wherein the pipe is fitted to the equipment housing by a configuration including: the bent portion of the pipe being provided on the external-facing side of the sheet member of the stay, the equipment-housing side of the sheet member of the stay contacting the equipment housing, the tip of the end portion of the pipe being confined within the tubular member of the stay, the tubular member of the stay being confined within the fluid passage of the equipment housing, and the O-ring extending and providing a seal between the tubular member of the stay and the fluid passage of the equipment housing.
 5. The pipe joining structure according to claim 4, wherein the fluid passage of the equipment housing comprises a spot-faced hole coaxially arranged with the fluid passage, the spot-faced hole and the projecting portion of the tubular member each have a diameter greater than inner portions of the fluid passage, a flange provided at a bottom end of the tubular member, the spool is formed between the flange and the projecting portion of the tubular member, and the end portion of the pipe is fixed to the tubular member of the stay by brazing.
 6. The pipe joining structure according to claim 4, wherein the fluid passage of the equipment housing comprises a spot-faced hole coaxially arranged with the fluid passage, the spot-faced hole and the projecting portion of the tubular member each have a diameter greater than inner portions of the fluid passage, the tubular member has a bottom end with a diameter less than the inner portions of the fluid passage, the bottom end of the tubular member is received in the fluid passage, the spool is provided above and adjacent the projecting portion of the tubular member, the projection portion of the tubular member abuts a peripheral edge contained within the spot-faced hole, and the end portion of the pipe is fixed to the tubular member of the stay by brazing.
 7. The pipe joining structure according to claim 4, wherein the sheet member of the stay has a screw hole, the housing equipment has a threaded hole, and the stay is fixed to the housing equipment by a screw passing through the screw hole of the stay and being threaded into the threaded hole of the equipment housing. 